The present invention relates to improvements in monitoring equipment for scuba divers. Scuba divers can swim to considerable depths and stay for long periods of time because they are provided with pressurized air tanks to supply air for breathing.
However, humans did not evolve as underwater creatures and therefore are not anatomically nor physiologically equipped to deal with certain hazards which are presented in diving. For example, diving in cold water can expose a diver to hypothermia, so divers typically wear wetsuits to protect them from the cold. Nonetheless, excessively cold water can still induce hypothermia.
Also, the supply of air to the diver in the tank is finite, limiting the time the diver can spend in the water. Moreover, the breathing of the compressed air at a substantial depth causes the dissolution of nitrogen in the air into the diver's blood. If this takes place over an extended period of time, the dissolved nitrogen reaches a level such that, upon decompressing, the nitrogen forms bubbles in the blood stream which can be excruciatingly painful and even lead to diver death. The dissolution of the nitrogen in the blood stream and the resultant bubble formation is known as "the bends". Prevention of the bends is accomplished by limiting the period of time at which a diver stays at excessive depths. Treatment is accomplished by having the ascent from excessive depths be gradual, to decrease the concentration of nitrogen in the bloodstream decreases gradually, so the nitrogen can be evolved gradually.
When decompression is required, the ascent from the maximum depth must begin early enough so that the diver has sufficient time to slowly ascend before the air in his tank is depleted.
Typically, diving in deep water takes place from a boat and one or more persons stays in the boat to assist in the event of an emergency below. Typically, the boat person has a signalling means to the diver to signal the diver when to begin his ascent in the event the diver has not already done so. However, up till now, the boat person has not had a convenient means to know the depth to which the diver has dived to be able to determine how quickly the ascent must be initiated to provide sufficient time for decompression. Also, the period of time required for decompression is determined largely by the depth to which the diver descends, so that the boat person needs to know not only how long the diver has been down, but how far down the diver has been and for how long at various depths. Moreover, in the event that the diver encounters other hazards, such as excessively cold water or perhaps becomes trapped beneath a ledge or within a submerged structure, the boat person needs to have some indication of this.
The present devices which permit a boat person to assist a diver simply do not provide the boat person with enough information to be of meaningful assistance to the diver to signal when to ascend or otherwise to treat a diver who may have ascended too quickly and be subject to the bends.
Accordingly, there is a need in the art for a diver monitor and process which will permit a boat person to follow parameters of the diver's dive.